A Gene for Autosomal Dominant Congenital Nystagmus Localizes to 6p12

Congenital nystagmus is an idiopathic disorder characterized by bilateral ocular oscillations usually manifest during infancy. Vision is typically decreased due to slippage of images across the fovea. As such, visual acuity correlates with nystagmus intensity, which is the amplitude and frequency of eye movements at a given position of gaze. X-linked, autosomal dominant, and autosomal recessive pedigrees have been described, but no mapping studies have been published. We recently described a large pedigree with autosomal dominant congenital nystagmus. A genome-wide search resulted in six markers on 6p linked by two-point analysis at θ = 0 (D6S459, D6S452, D6S465, FTHP1, D6S257, D6S430). Haplotype analysis localizes the gene for autosomal dominant congenital motor nystagmus to an 18-cM region between D6S271 and D6S455.     

Human leukemic K562 cells: differential effects of 5-azacytidine on DNA methylation of epsilon-, gamma-globin and 7SL RNA genes

5 Azacytidine ribonucleoside (5 Aza CR), greatly enhances erythroid differentiation of the K562(h) cell line, with a sharp increase of embryonic and fetal globin gene expression. This phenomenon is correlated with the undermethylation of gamma-globin but not of epsilon-globin, as the epsilon-globin gene is already extensively undermethylated before 5AzaCR induction. By contrast no variations in both DNA methylation and expression are observed in 7SL RNA genes.     

Microscopic anatomy of the ovary ofAlouatta caraya

The microscopic structure of theAlouatta caraya ovary is studied in different ages and reproductive stages. The most significant feature seems to be the presence in adult ovaries of abundant glandular interstitial tissue which occupies both the cortex and medulla. It seems to be derived from the theca interna of atretic follicles. Discrete luteinized masses are present in the medulla in all the ovaries observed. Invaginations of the surface epithelium are seen only in infant and juvenile ovaries. The development of cystic follicles seems to be a common pathway of atresia.     

The identification of trihydroxyeicosatrienoic acids as products from the incubation of arachidonic acid with washed blood platelets

Arachidonic acid is converted by washed platelets from man, horse and dog into a mixture of 8, 9, 12-trihydroxyeicosa-5, 10, 14-trienoic acid and 8, 11, 12-trihydroxyeicosa-5, 9, 14-trienoic acid (termed 8, 9, 12-THETA and 8, 11, 12-THETA respectively and THETA collectively). Gas chromatographic — mass spectrometric evidence of structure is discussed.     

Statistical-mechanical theory of passive transport through partially sieving or leaky membranes

The basic equations for multicomponent transport through partially sieving or leaky membranes are discussed from a statistical-mechanical viewpoint. They have the same mathematical form as the corresponding equations for open membranes, but differ in a discontinuous way from the equations for semipermeable membranes (since a "leak" in a semipermeable membrane constitutes a discontinuous or singular perturbation). Partially sieving membranes can be made to mimic semipermeable behavior through the introduction of characteristic time scales. They may approximate semipermeable behavior at short times, but always deviate at longer times.     

Expression of p53 gene in B-CLL peripheral lymphocytes.

The p53 tumor suppressor gene expression has been studied in 23 B-CLL cases at different clinical stages. The analysis failed to show a direct correlation with each stage, but the significantly lower frequency of a BglII RFLP in the pathologic population suggests a role of this gene in B-CLL. Northern Blot analysis showed the expression of p53 mRNA in all the B-CLL cases. A protocol for the RT-PCR methods was set up to study a very small amount of materials which should be better used for sequence analysis.     

Immunocytochemical detection of dendritic cell by S-100 protein in the chicken.

Positivity for S-100 protein in paraffin embedded chicken lymphoid tissue was found by using a polyclonal antibody against whole bovine S-100 protein. The S-100 protein-containing cells were observed in the locations which have been reported to contain avian dendritic cells such as the medulla of the bursal follicles, and the germinal centers and T-dependent areas in the spleen, Peyer's patches, caecal tonsil and Harderian gland. Positive cells were also found in the location where ellipsoid associated cell have been described, and between epithelial cells covering the Peyer's patches and the caecal tonsil, as well as between the cells lining the ducts within the Harderian gland. Macrophages were devoid of immunostaining. Our results confirm the location described elsewhere for chicken dendritic cells and indicate that S-100 protein can be considered as a cell marker for the identification of the chicken dendritic cell. Intraepithelial positive cells may be interdigitating dendritic cells in an unusual location (their function being the transport of the antigen from the epithelium to the diffuse lymphoid tissue), or cytotoxic T-lymphocytes which, in mammals, are immunoreactive for S-100 protein.     

The photoreaction center of Rhodospirillum rubrum mutant strain F24.1

Rhodospirillum rubrum strain F24.1 is a spontaneous revertant of nonphototrophic mutant F24 derived from wild-type strain S1. Strain F24 shows no detectable photochemical activity and contains, at most, traces of the photoreaction center polypeptides. Strain F24.1 has a phototrophic growth rate close to that of the wild-type strain (Picorel, R., del Valle-Tascón, S. and Ramírez, J.M. (1977) Arch. Biophys. Biochem. 181, 665–670) but shows little photochemical activity. Light-induced absorbance changes in the near-infrared, photoinduced EPR signals and ferricyanide-elicited absorbance changes indicate that strain F24.1 has a photoreaction center content of 7–8% as compared to strain S1. Polyacrylamide gel electrophoresis of isolated F24.1 chromatophores shows the photoreaction center polypeptides to be present in amounts compatible with this value. Photoreaction center was prepared from strain F24.1 and showed no detectable difference with that of strain S1. It is concluded that strain F24.1 photosynthesis is due entirely to its residual 7–8% of typical photoreaction center.     

The α-keto acids of branched-chain amino acids: Simplified derivatization for physiological samples and complete separation as quinoxalinols by packed column gas chromatography

By use of a relatively new mixed stationary phase, complete separation of the branched-chain α-keto acids as O-trimethylsilyl-quinoxalinol derivatives is achieved within 10 min by packed column gas chromatography. Precise quantification of less than 5 nmol of α-keto acids in biological samples is possible. In small aqueous samples the α-keto acids are directly derivatized without prior purification. Plasma need only be deproteinized by perchlorate and neutralized before derivatization. Average relative precision for determination of the three main branched-chain α-keto acids is ± 5.8%.